Circuit controller



B. W. JONES.

CIRCUIT CONTROLLER.

APPLICATION FILED NOV. 26, 1221.

Patented Oct. 10, 1922.

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BenjaminWJon es,

H i s Attorn 6y Patented Oct. 10, 1922.

. UNITED PATENT if FIQ BENJAMIN w. Joimsor scn'nnno'ranr, New YORK, AsSiIGNon To ELECTRIC COMP A1TY,. A oonronarron or new roan. I c

, omcurr oON'rR-OLLERL' Application' filed November 26, 1921.- Serial 801518931.

To all whom it marry-concern: i

Be it known that I, BENJAMIN-W-JDNEB, a citizen of the United States, residing at Schenectady, in the county of Schenectady, State of New York, have invented certain new and useful Improvements in Circuit Controllers, of which the following s a specification. a

My invention relates toan improved ar rangement for controlling the connection of electric translating devices to the source of supply; r 3 i a One of the objects of the invention is to provide an arrangement involving the use of twoelectroresponsive line switches which are successively closed only in case the conditions in the. controlled circuit a are such 1 that it issafe' for the translating -device,0r 'de vices-in the controlled circuit to be connected to a source of supply. It has heretofore been proposed to closethe electroresponsive line switches successively, since if a dangerous condition should be present in the controlled circuit and the contacts ofthe last line switch to close should be welded shut, the first line switch to close is nevertheless free to open in response'to the operationof a current responsivemea-ns. It has also been proposed that the arrangement should be such that after the first line switch: is thus opened, it

shall be prevented from being reclosed until after the second line switch has been opened, thereby preventing the welding shut of. the contacts of both line switches.

My invention is directed to improvements of circuit controllers of this general nature. In accordance with my invention, if after thefirst line switch is closed, the conditions of the controlled circuit are such that the second line switch should not be permitted to close, it is prevented from being closed until the dangerouscondition isremoved. Since the controlled circuit can not be connected to the sourceof supply unless it is safe to do so,the-contacts of both line switches are prevented from being welded shut. Further more, the arrangementfis such that in case close,

not rec'lose until the itshall be closed.

. 1n carrying my invention operator intends that .into effect, I

provide a master controller for the line switches which'may be manually or otherwiseuoperated, and an electroresponsive rel'ay'for controlling the second line switch to The relay winding is connected across the controlled circuit both before and after the line switches are closed, but when the first line switch closes, the relay windin is connected in series with aresistor whic is connected across the contacts of the second line switch, so that in case there is a low resistance path in the controlled circuit, due,

for instance, to a controller for oneof the,

translating devices in the controlled circuit being left in a running position, the relay will not be energized sufficiently to close and thereby energize the second line switch to close,since the relay winding will be connected in multiple with the low resistance path of the controlled circuit. I

For a better understanding of the invention, reference is had to the accompanying drawing wherein I haveillustrated one endbodimentwof theinvention for the purpose of explaining the principles thereof; Re-

ferringto the drawing, the circuitto be controlled 'has included therein'a plurality of electric translating devices, indicated by the armatureslO, l1 and 12 of electric motors.

Each of these electric motors is provided with a separate controller 13, 14 and 15 respectively. The electroresponsive line switches 16 and 17 are provided for connecting the controlled circuits to the source of supply 18. master controller 19 is provided for manually or otherwise controlling the closing of the lineswitches 16 and 17, and an electroresponsive relay 20 is provided for controlling the closing of the line switch 17. The winding of this relay is normally connected across the controlled circuit, and the arrangement is such that after the line switch 16 is energized to close by the closing of the master switch 19, the resistor 21 is connected across the switch contacts of the line switch 17, and the winding of the relay 20 is connected in series with the resistor 21 across the supply circuit. The energization of the winding of relay 20 is therefore indirectly responsive to the voltage drop across the contacts 01"? line switch 17, the second switch to close, and directly responsive to the resistance of the controlled circuit, so that unless the cont-rolled circuit is either open or the resistance thereof is high, the relay 20 will not be energized to close and thereby energize. the line switch 17 to close.

As thus constructed and arranged, and with the parts in their respective positions shown in the drawinmthe operation of my invention is as to1lows:The disconnecting switch22 will first be closed and then the pilot switch 23. It is assumed that the controllers 13, 14: and 15 are in their respective oil positions and that no dangerous condition is present in the circuit of any of the translating devices. In order to close the line switches 16 and 17, the master switch or push button 19 is closed. thereby energizing the windingof the line switch 16 through a circuit including,- the conductor 2&, conductor 25, conductor 26, winding of line switch 16, through the contacts of the current protective relays 27, 28, 29 and 80, to the other supply conductor. With the push button .19 in the closed position, the resistor 21 is connected across the contacts of the line switch 17 through a circuit including the conductors 2 1 and 25 and the contacts otE-the push button 19. The winding of the relay 20 is connected in series with the resistor 21 across the supply circuit through the contacts of the line switch 16. This relay is therefore energized indirectly responsively to the voltage drop across the line switch 17 and directly responsively to the resistance of the controlled circuit. It has been assumed that the controllers 13, 1 1 and 15 are all in their respective oii positions, and that no dangerous condition is present in the circuits of the translating devices 10, 11 and 12, so that the voltage drop across the winding of the relay 20 is substantially the voltage of the supply circuit, and the relay 20 will thereby be energized to close and complete the winding circuit for the line switch 17. The line switch 17 will thereupon close and connect the controlled circuit to the source of sup-- ply. The auxiliary switch 31 connectc. with the line switch 17 is provided for shr circuiting' the contacts of the push button 19, so that this push button may be released and the line switch nevertheless remain energized and closed.

In order to connect the motor arznatures 10, 11 and 12 to the source of supply, the respective controllers 13, 14 and 15 will be turned to the operative positions. In case an overload or some dangerous electrical condition should occur in the circuit or the motor armature 10, the current relay 28 will be energized sufficiently to pick up its contacts and open the circuit for the windings of the line switches 16 and 17. The current relay 28 will drop its contacts when the line switches are open, but the controlled circuit will not be reconnected to the source of supply. That is because of the fact that the master switch or push button 19 is in the open posit-ion. If all the controllers 13, 14 and 15 are not returned to their respective oil" positions, the line switch 17 is prevented from being reclosed by the operation of the master switch 19. Thus, closing the master switch 19 will energize the line switch 16 to close as before, but the winding of the relay 20' will not be sutliciently energized to close, and the winding of the line switch 17 is thereby prevented from being energized. That is because of the fact that the resistor 21 is connected in series with a multiple circuit having the relay winding in one branch and the circuit or circuits through the translating device or devices in another branch or branches. The operator is thus warned that some dangerous condition is present in the controlled circuit, and his attention will be called to the fact that probably one or all of the controllers 13, 14 and 15 are not in their respective off positions. He will. then re member to return the controllers to their respective ofl' positions before again attemptingto connect the controlled circuit to the source of supply. Ii. the controllers 13, 14: and 15 are returned to their respective off positions the low resistance shunt around the winding of the relay 2,0 is removed so that operating the master switch 19 will energize the line switch 16 to close as before and the relay 20 will thereby be energized to close its contacts and energize the line switch 17 to close as previously explained. If the line switch 17 is closed. the relay 20 is energized across the con trolled circuit so as to maintain the energization of the line switch 17 until a dangerous condition occurs in the controlled circuit. If, for example. there should be a short circuit condition in the armature 10 when the operator moves the controller 13 from the off to an operative position, the current relay 28 will be energized to open and thus cause the line switches 16 and 17 to open as previously explained. The operator is thus ap-prized oi? the fact that there is a dangerous condition in this cir cuit, and he will lrnow that before he can continue with the operation oi the motors 10, 11 and 12, this dangerous condition must be removed. It will also be observed that the arrangement prevents the closing; of both line switches in case there should be a short circuit between the conductors of the controlled circuit, even though the ill) controllers are in their ofi positions. Furthermore, it is not necessary to run any wires to the separate controllers other than the main conductors in which the translating devices are included.

In accordance with the provisions of the patent statutes, I have described, the prin-' ciple of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof, but I desire to have it understood that the apparatus shown is only illustrative and that the invention may be carried out by other means.

What I claim as new and desire to secure by Letters Patent of the United States, is

l. The combination in a circuit controller of two normally open electroresponsive line switches, a master controller therefor, an electroresponsive relay for controlling the second of said line switches, and connections whereby the operation of the said master controller energizes the first linev switch to close and energizes the winding of the said relay responsively to the resistance of the controlled circuit so that the relay will subsequently automatically operate and energize the second line switch to close only in case the resistance of the controlled circuit is above a predetermined value.

2. The combination in a circuit controller of two normally open electromagnetic line switches, a master controller therefor, a normally open electromagnetic relay for controlling the second of the said line switches, and connections whereby the operation of the said master controller energizes the first line switch to close and energizes the w1nd ing of the said relay responsively to the resistance of the controlled circuit so that the relay will subsequently automatically close and energize the second line switch to close only in case the resistance of the controlled circuit is above a predetermined value.

3. The combination in a circuit controller of two normally open electromagnetic line switches for controlling the connection of a translating device to a source of supply, a master controller for the said line switches, an electromagnetic relay having its winding connected across the circuit controlled by the said line switches for controlling the second oi said line switches, and connections whereby the operation of the said master controller energizesthe first line switch to close and thereby connects the winding of the said relay across the switch contacts of the second line switch in multiple with a translating device in the controlled circuit so that the relay will automatically 'close and energize the second line switch to close only in case the resistance of the controlled circuit is above a predetermined value.

4. The combination in a circuit controller switches for controlling the connection of a translating device to a source ofsupply, a

master controller for the said line switches,

an electromagnetic relay having its winding connected across the circuit controlled b the said line switches for controlling the second of said line switches, a resistor, and connections whereby the operation of the said master controller energizes the first line switch to close and thus connect the said resistor across the contacts of the second line switch and the winding of the said relay in a multiple circuit with the said translating device, with the said multiple circuit in series with the said resistor across the source of supply'so that the said relay will automatically close and energize the second line switch to close only in case the resistance of the controlled circuit is above a predetermined 'value.

6. The combination in a circuit controller of two normally open electromagnetic line switches for controlling the connection of a translating device to a source of Supply, a

separate controller for the said translating device, a master controller for the'said line switches, an electromagnetic relay for controlling the second of said line switches,

a resistor, and connections whereby. the operation of the said master controller energizes the first line switch to close and thus connect the said resistor across the contactsof the second line switch and the winding of the said relay in multiple with a circuit through the said separate controller in series with the said resistor across the source of supply so that the said relay will automatically close and energize the second line switch to close only in case the said controller is operated to open the circuit through. the said translating device.

7. The combination in a circuit controller of two normally open electromagnetic line switches for controlling the connection of a plurality of translating devices to a source of supply, a separate controller for each of said translating devices, a master controller for the said lineswitches, an electromagnetic relay having its winding connected across the circuit controlled by the said line switches for controlling the second of said line switches, a resistor, and connections source of supply so that the said relay will 10 automatically close and energize the second line switch to close only in case the circuit or circuits through the said translating devices are opened by the operation of the said separate controllers.

In witness whereof, I have hereunto set my hand this 25th day of November, 1921. BENJAMIN W. JONES. 

